RPC: Authentication error; why = Client credential too weak
 

OS: RHEL 6.2 , 2.6.32-220.el6.i686

I created a service using RPC and is compiled using rpcgen and gcc.

When I try to run the service I get the following Error :

Cannot register service: RPC: Authentication error; why = Client credential too weak

I restarted rpcbind with argument -i. Now able to register the RPC process.

man page shows that -i meaning insecure mode. Do I need to rewrite the program to have secure registration? If so any example please.

what causes insecure mode?

RPC has various security options ranging from None (Unix) through DES to possibly stronger recent versions I've not investigated. I'm afraid I last did RPC programming before the US allowed the relevant libraries to be exported so I didn't use those security features but added my own.

... and you definitely want to run your RPC service with some level of cryptographic security and client-authentication. Even if you do not actually care if the data being passed is unintelligible (e.g. it's internal-only or passing through a VPN tunnel already), you do want other things like message-integrity and provenance. Take the time to really study these features closely.

An overly-trusting RPC service is a "Bobby Tables problem" at worst, but a source of unacceptable lack-of troubleshooting at best.